Ladder-jack.



L. N. BOURDEAU.

LADDER JACK. APPLICATION FILED ocT.14. 1915.

1,226,853. Patented May 22, 1917."

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LADDER JACK.

APPLICATION FILED o'cT.14. 1915.

Patented May 22, 1917.

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Specification of Letters Patent. Pdtfitd Application fled 0ctober14, 1915. Serial 110.555852.

To all whom it may concern: Beit known that I, LEON N, B URDEAU, of Rock Island, .inthe county of Rock Island and State of Illinois, have invented certain new and usefullmprovements i11Ladder-J'acks; and-I do hereby declare the fol lowingto he a full, clearyand exact description of the invention, such aswill enable others skilled in the art to which it appertains to -make and use the same;

My invention'relates to ladder jacks, and the primary object -'of the invention is to provide an) improved" and eflicient device of this character embodyingbut few parts, and'one'cap'able of being readily assembled for use and whenso assembled of being raised and lowered on a ladder without disturbing the horizontal position of the platform= supported thereby,- or rendering necessary the removal of tools, etc. from the platform;

V In the accompanying drawings, Figure 1 is a view in perspective of one of the complementary jacks applied to a ladder. Fig.

2 isa .v-lew in endelevation showing the bracket in" position? Fig. 3 is a sectional view on line 3-3, Fig. 1. -Fig. at is aperspectiveview showingthe parts in unassembled position I Referring to the drawings, 1 designates a portionv of a ladder, which, with another or others, forms a base upon which a temporary platform 2 is designed to'be supported. One of the stiles of each ladder forms the supporting and guidin g means for a bracket 3 to which the platform members are secured. The acks must be used in pairs, or in series, one on each ladder,

and a description of one will be sufiicient. Each bracket comprises two interlocking members 4L and 5, the member 4 being of L-shape in cross section and having an upwardly extending portion 6, while the member 5 is of T-shape in cross section, thepart 7 thereof being designed to closely fit against part 8 of the member 4 so as to form a right angular connection therewith. The part 7 has lugs 9 near its top and bottom which extend through openings in the part 8, cotter pins 10 securing the two parts together. It will be seen that as thus assembled the member 1 will bear against the stile of the ladder along its front face and its outer side, while the member 5 W111 parallel the rear surface and a part of the inner side of the ladder. The bracket is thus held in guiding position on T the stile.

12 and 13 designate extensions at the lower rear ends of the members l and 5, such extensions being bored to receive a pintle 11 forming the'pivot for a horizontally-arranged rearwardly-extending plat form-supporting arm 15, to the free end of which is pivotally secured-a bracing bar 16. The upper end of this bar has a series of notches 17 one of which is designed to receive a headed stud 18 projecting outwardly from the portion 6. 19'is an auxiliary brace pivoted to the bar .16 by any suitable means and having its upper end of hook form to embrace a ladder rung. The point of connection of the auxiliary brace to the bar 16 may be made at any one of a series of points 20 which are spaced relatively to the notches 17. In addition to the auxiliary brace 19, and to prevent a twisting strain on the stile, I provide a hook 19 suitably pivoted to brace bar 16 and curved throughout its length so that its upper end may engage a second headed stud 18 The bracket is held in the desired position on the stile by a depending arm 21, the lower end of which is grooved, as at 22, to receive the rung of the ladder, while the upper end is formed with a. laterally extending sleeve 23 by which the arm is pivotally secured to the bracket through the medium of pintle 1 1. An extension 24 of the sleeve projecting. beyond the vertical plane of the supportin'garm' 15 is a means of positioning the arm on the ladder rung. It is obvious that the weight of the platform is equally distributed and is not wholly taken up by the depending arm 21, the part 8 of the member 4 and the part 7 of the member 5, owing to the inclination of the ladder, effecting a gripping action on the stile which thus carries a portion of the weight.

A handle 25 pivoted at 26 to the lower end of the part 8 of the bracket has an angularly disposed arm 27 which is designed to engage the underside of the supporting arm 15. An upward pull on the handle will move the bracket and automatically disengage the arm 21 from the ladder rung. After the parts have been raised or lowered to the desired position, the arm 21 may readily be guided to a rung-engaging position by the extension 24 thereof. Thereafter the auxiliary brace may be secured to an upper ring.

The operation of my jack will be apparent. After the bracket has been secured in place, the platform supporting arm is attached thereto by pintle 14:, which latter also carries the rung-engaging arm 21. The bracing bar 16 is then placed in position, with one of its notches 17 engaging the stud 18, the other stud receiving the hook 19 The auxiliary brace 19 is then secured to the bar 16 and to one. of the rungs of the ladder. The platform 2 may then be extended from one jack to another. It will be observed that by the use of my invention an operator may readily and easily move his platform up or down without disturbing any article on the platform, the latter at all times retaining its horizontal position. The notched brace bar permits of adjustment where required by varying inclinations of the sup porting ladders.

I claim as my invention:

1. In a ladder jack, a stileengaging bracket, a platform supporting arm pivoted to the lower end of said bracket, a bracing bar at the opposite end of .said arm, said bar engaging the upper end of said bracket, and

a rung-engaging member pivoted to said bracing bar.

2. In a ladder jack, a stile-engaging bracket comprising separable sections, a platform supporting arm pivoted to the lower end of said bracket, a bracing bar at the opposite end of said arm, said bar en- Copies of this patent may be obtained for 4. In a ladder jack, a stile-engaging bracket, a platform supporting arm pivoted to the lower end of said bracket, a bracing bar at the opposite end of said arm, said bar engaging the upper end of said bracket, a rung engaging member pivoted to said bracing bar, and a handle pivoted to said bracket and designed to lift said platform supporting arm to disengage said rung engaging member.

5. In a ladder jack, a stile engaging bracket, a platform supporting arm pivotally mounted 011 said bracket, a bracing bar connected to said arm, said bar being mounted with means for adjustably engaging the bracket, an auxiliary brace and a rung-engaging member pivoted to said bar, the auxiliary brace being adapted to engage the bracket.

6. In a ladder jack, a stile engaging bracket, a platform supporting arm pivotally mounted on said bracket, a bracing bar connected to said arm and engaging the bracket, means for pivoting the supporting arm on the bracket, and a rung engaging member pivotally mounted on the bracket by said means.

7. In a ladder jack, a stileengaging bracket comprising separable sections, means for connecting the sections together, a platform supporting arm pivotally mounted between the lower ends of said sections, a bracing bar connected to said arm and engaging one of the sections of the bracket, and an auxiliary brace carried by said bracing bar engaging the other section of the bracket.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

LEON N. BOURDEAU.

Witnesses:

CLYDE S. WALKER, WVILLIAM C. ALLEN.

five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

